For stacking currency, the 20c piece is the sweet spot. Best ratio, metal - value. Plus large enough that 10 or 20 will get you some basics such as bread and milk etc... Money bags hold $10 worth so 10 x = $100 easy enough. 50c the ratio is too small not even 30% also they are large and heavy. 50c are my least collected coin. PITA IMO This is a side hoard more than a back up reserve basis. However a few hundred dollars is easy enough to store and have as backup. After that $5 and $10 make sense to me for larger purchases. $100 and $50 notes are good but if someone doesn't have the change you may not be able to complete the trade/transaction or have to give up getting change and pay more ?
